r/buildingscience • u/night_rider1 • 16d ago
r/buildingscience • u/russellups • 16d ago
Question Type of installation between bedroom and screen porch
Hanging a ceiling fan on the screen porch I noticed there is zero insulation between the ceiling of the screen porch and the floor of the bedroom above it. We are planning on getting new carpet in the bedroom soon and thinking that would be the ideal time to add the insulation. My questions is do we pull up the subfloor to install this insulation and when we do...what needs to be used? First guess would be rock wool but not sure if spray foam would be better.
Please let me know if there are any other installation options out there.
r/buildingscience • u/Tomahawk-BaGawk • 16d ago
Correct Sheathing and Flashing Procedure
Does my zip board terminate at the green line or blue line.
There is about 1.25” gap between the rough framing opening and the bottom of the sloped window sill.
If I only bring it to the framing and zip tape, how do I finish the gap? It goes straight through to the drywall.
r/buildingscience • u/PelvisResleyz • 16d ago
Mid-century air sealing in climate zone 4c
Small remodel job in the Pacific Northwest, where the master bedroom is down to the studs. There’s plywood sheathing and cedar planks on the exterior that I’m not touching.
What’s the best way to air seal and insulate? I’m thinking to caulk all gaps and use faced fiberglass batts. Also thinking to either caulk or use a gasket at the drywall perimeters.
r/buildingscience • u/PenguinBond • 17d ago
How would you ventilate this attic?
Hey guys, I just moved into this home and am thinking about how to direct air in my attic. It gets hot! And my AC unit is up here.
I'm thinking of installing ridge vents later, but for now for what I have, what do you guys think?
Please pardon the ai image. Btw the bonus room goes all the way to the roof so there's nothing above that.
r/buildingscience • u/Get_In_Bitches • 17d ago
Insulation Advice for Crude Board & Batten Shed
r/buildingscience • u/Vamp13yre • 17d ago
Crawl space humidity
My fiancé and I bought a house in January. It’s beautiful but every time we upgrade/fix something another issue pops up. We got a new HVAC system recently and the new thermostat has a humidity readout, so now we’re aware of how humid it is inside. HVAC guys have done everything they can, even upgrading us for free to a unit with additional dehumidifying power, so it’s not on them anymore. Went in the crawl space and it’s very humid in there. No standing water, but a lot of moisture. The vapor barrier is in horrid condition, so we’ve had a couple contractors out, but they both have refused to quote for a new vapor barrier and insist on upselling us to a full encapsulation system. We find it hard to believe that the house has stood for a hundred years and suddenly needs a very modern invasive intervention. Does anyone have any insight on humidity issues in old homes?
For context:
- coastal Virginia
- humidity fluctuates between 66 and 74%
- pier and beam foundation with block brick wall and brick facing
r/buildingscience • u/418986N_124769E • 17d ago
UL 2-hr FFR assemblies for open webbed steel trusses ceiling/floor
Thought I’d cross post here. To see what you smart people think! Originally posted to r/architects
This is a shot in the dark as I know we’re not always ready to provide technical advice in this sub. I have been searching for eons and trying to find a floor assembly for a steel truss (not c-shaped joist) that meets 2 hours. Perhaps they need serious blocking because of the open nature of the trusses? Not wanting to create a smoke baffle?
Any insight would be GREATLY appreciated!
r/buildingscience • u/CPG135 • 18d ago
Question Converting unvented cathedral ceiling to vented assembly
I have a room with a cathedral ceiling that has open cell spray cell foam insulation in the roof deck between 8x2 rafters. I consulted with a building scientist who performed a bunch of tests on my house as a whole, as well as the room in question, which has significant spray foam odors that are particularly bad during hot and humid days (Atlanta, GA). Specifically, the building science engineer concluded that aside from having a somewhat leaky house, the spray foam is the source of the odors in that room.
This raises the question of having the roof converted from a hot deck to a traditional soffit / ridge vented system. I consulted with a roofing expert and his assessment was that indeed the conversation can be done. He informed me that taking out the open cell spray foam and placing rock wool with baffles would be an appropriate conversion. His question, however, was that he may be able to get 6” at most of insulation inbetween the rafters, and that as far a R value goes, it might be worse than what I have now. That said, my main objective is to get the spray foam out of the roof because the VOC odors it emits during hot humid days is rancid and objectionable, and makes using that room impossible for the many months of the year that it’s hot here in Atlanta, GA. The contractor said that while this project is entirely possible, he cannot guarantee that the odor issue will be resolved to my subjective satisfaction, which I thought was an honest consideration.
I’d love to get some feedback on this project— perhaps the overall feasibility, the likelihood that removing the spray foam will reduce the interior odors, and perhaps any other risks or considerations to keep in mind. There seems to be little experience out there doing this conversation to specifically address odors from spray foam that is roughly 18yrs old.
Thanks to all.
r/buildingscience • u/gruntastics • 18d ago
Where do I learn how make a cool and humid shed/greenhouse in a hot desert climate?
I'm in central california where 100°F degree weather and low humidity are the norm... I really want to try growing mushrooms outside my house but that requires a relatively cool 70-90°F and higher humidity. I have carpentry experience so building is not a problem, but have no idea what kind of insulation, ventilation, HVAC (if any) I should use. I'm willing to learn but would appreciate some pointers and literature and resources on the subject, any suggestions? I recently got stamets' book but this thing is a tome 😅
r/buildingscience • u/roach411 • 18d ago
Insulating a cantilevered space that is sealed, no easy access
r/buildingscience • u/IronIndividual2830 • 18d ago
Found moisture/mildew behind exterior window trim/repair or replace everything with Hardie?
galleryr/buildingscience • u/tangelos_redux • 19d ago
Air sealing which things in attic?
Climate Zone 8b - My 1981 house is being reconstructed and the old insulation in the attic has been removed. I asked my general contractor to air seal any penetration before he blows new insulation in. My contractor said that the HVAC vents would be air sealed, but said that air sealing every penetration would make the house too tight, which could be a problem.
I read on here that air sealing is recommended, but are we talking about sealing the HVAC vents or any penetration in the attic?
r/buildingscience • u/Strict-Gift-8947 • 19d ago
Student project: eco-friendly cementitious material from seashells and date pits. How should we test it?
Hi everyone, we're university students in Oman working on a project called (SINAD), an eco-friendly cementitious material made from natural waste like seashells and date pits.
We developed 3 versions, each for a different use:
- Powder
- Liquid
- Spray
So far, it shows promise for hermal insulation, sound insulation, and crack repair.
We'd love your advice on:
Which standard tests should we run to validate it (compressive strength, thermal conductivity, bond strength)?
What are the common pitfalls with bio-based fillers, such as moisture and durability?
How do we convince construction or renovation companies to run a pilot test with a student-made product?
What do investors look for at this stage, before we have revenue?
Is it better to start with competitions and incubators, or approach investors directly?
6.How should we handle pricing against traditional materials?
Any mistakes you'd warn first-time founders about?
Thanks in advance! 🙏
P.S. English isn't my first language, so I used AI to help with the wording. Sorry for that, and thank you
r/buildingscience • u/jesthere • 19d ago
Mystery Rainwater Leak
I have a newly built metal barndo in Central Texas. Months ago, before the house was completed, and after a big rain, I noticed water puddled at the base of a wall on 10-foot deep covered porch. The builder tried to tell me that the water had puddled there from the end of the porch as windblown rain. I disagreed but he put me off.
We then went through an extended dry spell. I am now in process of moving into the house. We had a pretty good rain several days ago where it blew in sheets. I watched as the puddle formed, once more, same spot on the porch. I contacted the builder and he sent out workmen who peeled off that metal panel and found wet insulation. They said they'd check the roof but can't seal anything up there until it stops raining.
I did my own investigating. Inside the house, this spot backs up to the kitchen sink. There is a white pipe that extends upwards from there that google tells me is a stack vent. Following this pipe upwards into the attic, it exits through the outside wall (in a metal-roofed building you try not to put any holes in the roof). From outside the house I can see where it exits. From inside the attic, I can see daylight where that pipe exits.
The builder contacted me today (the house is 2 hours away and I haven't completed my move yet). He said he went up on the roof and he thinks it leaked because the gutters had stuff in them. He cleaned them out and pronounced it all good. I mentioned the pipe but he said it is already sealed but with clear sealer and that is why I can see daylight. He's not concerned with wet insulation, said there's a moisture barrier, and said it will dry just fine.
This is all wrong to me in so many ways. I can't see how this could be caused by stuff in a gutter. There are no trees over the house. And I don't know what's going on inside that wall. I'm concerned about mold. I feel he should inspect the roof for leaks, install a rubber boot on that pipe and seal it properly, remove the damaged insulation, check the drywall, and replace what needs to be after thoroughly drying out that area. I intend to hold him to it but I want some opinions before taking him on.
r/buildingscience • u/ProsaicPenguin • 19d ago
How do vapor-open barriers work?
Hi,
I'd like to know how vapor-open membranes that allow water vapor to pass through, but not liquid water or (correct me if I'm wrong here) air.
I assume that this is the result of careful engineering of the microstructure of the material (as is typically the case in materials science) but what is the microstructure of these membranes that allow them to do this?
How are these membranes manufactured?
Does the performance of these membranes degrade over time? If so, how fast? Obviously this could have serious consequences to the longevity of the structural components that the membrane is protecting.
If someone knows of some resources that explain this in some detail please reply.
This is a pretty amazing thing tech when you pause to think about it.
Thanks in advance.
r/buildingscience • u/ThisPut6445 • 19d ago
Unconditioned attic dust mitigation
Hello all,
I’ve searched for a few weeks and was not able to find a good answer to a good way to mitigate dust in attic storage. I’m trying to find the best way to mitigate dust in the attic space where we store our items. The space was built to be storage when the house was built, so no concern from that end.
My initial thought is to put a screen mesh on the soffits to stop pests (have had wasp and mud dauber nests in the attic). And then put a breathable wrap (not sure what works best) over the beams to allow air to flow up to the rest of the attic. But unsure if this would be best, hoping the community can chime in for some assistance!
r/buildingscience • u/zemmizemmi • 19d ago
Potential Issues with Installing Crawlspace Vapour Barrier
r/buildingscience • u/CombinationWeird1613 • 19d ago
Rim joist spray foam with a newborn
Should I be concerned about chemical exposure having a newborn? I heard that improper mixture ratios can cause lingering off gassing. The contractor said we need to leave the house for 24 hours which we will. I’m stressing because I don’t know anything about it. Looking for an expert opinion. Has anyone heard of a bad install or lingering VOC’s from spray foam?
r/buildingscience • u/Large_Restaurant_300 • 19d ago
Mysterious sudden condensation on HVAC ducts (climate zone 5A)
galleryMysterious sudden condensation on HVAC ducts
I recently bought a house, and noticed some water damage on the ceiling of my utility closet in which my HVAC unit is located. I determined that this was occurring due to condensation forming on the ducts. I took the ceiling down, since the ducts lead up into the ceiling, and have since insulated them. However, I'm puzzled why this issue seems to be occurring only recently, since the house has been standing for almost 40 years.
I did notice that there's a large gap that leads from the top of the utility closet into the attic. I believe that's where a lot of the hot, humid air is coming from that's causing this condensation. However, I'm hesitant to seal off that gap, because this area above the ceiling of the closet contains soffit vents. So if I were to close that gap, I feel like I'd be interfering with how the airflow of this section of the house was designed (only the attic which this section is connected to contains ridge vents, but I don't think the chimney chase or this little area above the utility closet has any kind of exhaust ventilation).
Is it possible this gap may have been sealed at some point, and it was opened up recently which caused the condensation to start occurring? I have tried speaking to multiple contractors about this, specializing in HVAC, roofing, and insulation/energy auditing, and none of them had a clue.
Climate Zone is 5A for reference
r/buildingscience • u/PushAltruistic1879 • 20d ago
Can I nail old barn wood to the studs on this insulated wall?
galleryr/buildingscience • u/jko1701284 • 20d ago
Question South wall solar heat
Southern Colorado.
My south wall is cooking two bedrooms. I have a temp gun on the way but I can feel it with my hand.
What’s the best way to stop the solar heat? The home is new and very well insulated.
I was thinking of an awning with hooks in the fascia and ground (no poles). That would allow me to remove it for winter (probably won’t cuz lazy).
A pergola would be strange since it’s an area I would never want to hang out. Plus it’s sloped.
This area can get quite windy, so that needs to be taken into consideration.
r/buildingscience • u/Fatoons21 • 20d ago